
    <!DOCTYPE html>
    <html lang="zh-CN">
    <head>
      <meta charset="UTF-8">
      <meta name="viewport" content="width=device-width, initial-scale=1.0">
      <title>Kafka的ACK机制有那些 - 交互式测验</title>
      <style>
        @import url('https://fonts.googleapis.com/css2?family=Noto+Sans+SC:wght@400;500;700&display=swap');
        
        body {
          font-family: 'Noto Sans SC', sans-serif;
          background-color: #f4f7f9;
          color: #333;
          display: flex;
          justify-content: center;
          align-items: center;
          min-height: 100vh;
          margin: 0;
          padding: 20px;
          box-sizing: border-box;
        }
        
        .main-wrapper {
            position: relative;
            width: 100%;
            max-width: 900px; /* Wider to accommodate buttons */
            display: flex;
            justify-content: center;
            align-items: center;
        }

        .quiz-container {
          background-color: #ffffff;
          border-radius: 16px;
          box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
          width: 100%;
          max-width: 700px;
          overflow: hidden;
          z-index: 10;
        }

        .quiz-header {
          background-color: #4a90e2;
          color: white;
          padding: 20px 30px;
          text-align: center;
        }

        .quiz-header h1 {
          margin: 0;
          font-size: 24px;
          font-weight: 700;
        }
        
        .quiz-header p {
            margin: 5px 0 0;
            font-size: 14px;
            opacity: 0.9;
        }

        .quiz-body {
          padding: 30px;
        }

        .progress-bar {
            display: none; /* 隐藏进度条 */
            width: 100%;
            background-color: #e0e0e0;
            border-radius: 5px;
            height: 10px;
            margin-bottom: 20px;
        }

        #progress-indicator {
            height: 100%;
            width: 0%;
            background-color: #4caf50;
            border-radius: 5px;
            transition: width 0.3s ease;
        }

        #question-container {
          margin-bottom: 20px;
        }

        #question-text {
          font-size: 18px;
          font-weight: 500;
          line-height: 1.6;
          margin-bottom: 25px;
        }

        .options-list {
          list-style: none;
          padding: 0;
          margin: 0;
        }

        .option-item {
          background-color: #f8f9fa;
          border: 1px solid #dee2e6;
          border-radius: 8px;
          padding: 15px;
          margin-bottom: 12px;
          cursor: pointer;
          transition: background-color 0.2s ease, border-color 0.2s ease;
        }

        .option-item:hover {
          background-color: #e9ecef;
        }
        
        .option-item.selected {
            background-color: #d1e7fd;
            border-color: #4a90e2;
        }

        .quiz-footer {
          padding: 20px 30px;
          display: flex;
          justify-content: space-between; /* 将按钮分布在两侧 */
          align-items: center;
          min-height: 65px; /* Reserve space */
        }

        .nav-btn {
          background-color: #4a90e2;
          color: white;
          border: none;
          border-radius: 8px;
          padding: 10px 20px;
          font-size: 16px;
          font-weight: 500;
          cursor: pointer;
          transition: background-color 0.2s ease, transform 0.2s ease;
          box-shadow: 0 4px 12px rgba(0,0,0,0.15);
        }
        
        #next-btn {
            background-color: #28a745;
        }

        .nav-btn:hover {
          background-color: #357abd;
          transform: scale(1.05);
        }
        
        .nav-btn:disabled {
            background-color: #a0c3e8;
            cursor: not-allowed;
            opacity: 0.7;
        }

        #result-container {
            border-top: 1px solid #eee;
        }
        
        .result-box {
            border-radius: 8px;
            padding: 20px;
            margin-top: 20px;
        }
        
        .result-box.correct {
            background-color: #d4edda;
            border: 1px solid #c3e6cb;
            color: #155724;
        }

        .result-box.incorrect {
            background-color: #f8d7da;
            border: 1px solid #f5c6cb;
            color: #721c24;
        }
        
        .result-box h3 {
            margin-top: 0;
        }

        .explanation-text {
            margin-top: 15px;
            line-height: 1.7;
        }
        
        .source-text {
            font-style: italic;
            font-size: 14px;
            margin-top: 15px;
            color: #555;
        }

        
        .final-score-container {
            padding: 40px;
            text-align: center;
        }
        .final-score-container h2 {
            margin-top: 0;
            margin-bottom: 30px;
        }
        .score-summary {
            display: flex;
            justify-content: center;
            gap: 20px;
            margin-bottom: 40px;
            flex-wrap: wrap;
        }
        .score-card {
            background-color: #f8f9fa;
            border-radius: 12px;
            padding: 20px;
            width: 180px;
            box-shadow: 0 4px 12px rgba(0,0,0,0.05);
            border: 1px solid #e9ecef;
        }
        .score-card h3 {
            margin: 0 0 10px;
            font-size: 16px;
            font-weight: 500;
            color: #555;
        }
        .score-card p {
            margin: 0;
            font-size: 28px;
            font-weight: 700;
            color: #333;
        }
        .score-details table {
            width: 100%;
            font-size: 16px;
        }
        .score-details td {
            padding: 4px 0;
        }
        .score-details td:last-child {
            text-align: right;
            font-weight: 700;
        }
        .report-actions button {
            background-color: #fff;
            border: 1px solid #ccc;
            border-radius: 8px;
            padding: 12px 25px;
            font-size: 16px;
            cursor: pointer;
            margin: 0 10px;
            transition: background-color 0.2s ease, border-color 0.2s ease, transform 0.2s ease;
        }
        .report-actions button:hover {
            background-color: #f1f1f1;
            border-color: #bbb;
            transform: translateY(-2px);
        }
        .report-actions button.primary {
            background-color: #28a745;
            color: white;
            border-color: #28a745;
        }
        .report-actions button.primary:hover {
            background-color: #218838;
        }
        
        .hint-container {
            background-color: #e0f7fa;
            border: 1px solid #b2ebf2;
            border-radius: 8px;
            padding: 15px;
            margin-top: 20px;
            color: #006064;
            font-size: 15px;
            line-height: 1.6;
            display: none; /* 默认隐藏 */
        }
      </style>
    </head>
    <body>
      <div class="main-wrapper">
          <div class="quiz-container">
            <div class="quiz-header">
              <h1>Kafka的ACK机制有那些 - 交互式测验</h1>
              <p>检验你对文档内容的理解程度</p>
            </div>
            <div id="quiz-content">
                <div class="quiz-body">
                    <div class="progress-bar">
                        <div id="progress-indicator"></div>
                    </div>
                    <div id="question-container">
                      <p id="question-text"></p>
                      <ul class="options-list" id="options-list"></ul>
                    </div>
                    <div id="result-container"></div>
                    <div id="hint-container" class="hint-container"></div>
                </div>
                <div class="quiz-footer" id="quiz-footer">
                  <button id="prev-btn" class="nav-btn">上一题</button>
                  <button id="hint-btn" class="nav-btn" style="background-color: #ffc107; color: #333; box-shadow: 0 4px 12px rgba(255,193,7,0.3);">提示</button>
                  <button id="next-btn" class="nav-btn">下一题</button>
                </div>
            </div>
          </div>
      </div>

      <script>
        const quizData = [
  {
    "question": "在Kafka生产端配置中，当 `acks` 设置为 `all` 时，它代表了什么含义？",
    "options": [
      "生产者只需要等待leader副本确认消息即可，这是一种性能和可靠性的折中。",
      "生产者会等待ISR（In-Sync Replicas）中的所有副本都确认消息，提供了最高的消息可靠性。",
      "生产者发送消息后不等待任何确认，吞吐量最高但可能丢消息。",
      "生产者会等待集群中所有的Broker（无论是否在ISR中）都确认消息。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "`acks=all` 提供了最高级别的消息保证。生产者会等待分区的所有同步副本（ISR）都接收到消息后，才认为消息发送成功。这能最大限度地防止因leader节点宕机导致的消息丢失，但会增加消息发送的延迟。",
    "source": "文档中「生产端确认机制」部分",
    "hint": "文档中提到，这种配置“提供了最高的消息可靠性”。想一想最高可靠性需要等待哪些副本的确认？"
  },
  {
    "question": "在何种场景下，将Kafka生产者的 `acks` 参数设置为 `0` 是最合适的选择？",
    "options": [
      "对消息可靠性要求极高，不允许任何数据丢失的金融交易场景。",
      "需要保证消息被至少一个副本成功接收，以实现基本可靠性的场景。",
      "对消息丢失不敏感，但追求最高吞吐量和最低延迟的场景。",
      "当消费者需要手动提交偏移量以确保精确一次处理的场景。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "`acks=0` 意味着生产者发送消息后不会等待任何来自服务器的确认。这种“即发即忘”的模式延迟最低，吞吐量最高，但如果Broker在收到消息后、数据落盘前发生故障，消息就会丢失。因此，它适用于可以容忍少量数据丢失的场景，如日志收集或非关键指标监控。",
    "source": "文档中「生产端确认机制」部分",
    "hint": "思考一下哪种配置的描述是“可能会导致消息丢失”但性能最好？"
  },
  {
    "question": "根据文档描述，Kafka消费端采用“自动提交偏移量”机制可能带来什么主要风险？",
    "options": [
      "会显著增加消费者的处理延迟，因为每次消费都需要同步等待偏移量提交。",
      "如果消费者在处理消息时发生故障，可能导致消息重复消费或丢失。",
      "必须在代码中显式调用 `commitSync()` 方法，增加了代码复杂性。",
      "会导致生产者发送消息的速率变慢。"
    ],
    "correctAnswerIndex": 1,
    "explanation": "自动提交是按时间间隔进行的。如果消费者拉取了一批消息并开始处理，但在处理完成前自动提交了偏移量，此时若消费者崩溃，重启后会从已提交的偏移量之后开始消费，导致未处理完的消息丢失。反之，如果处理完消息但还没来得及自动提交就崩溃了，重启后会重复消费这批消息。",
    "source": "文档中「消费端确认机制」-「自动提交偏移量」部分",
    "hint": "文档中提到：“...如果消费者在处理消息时发生错误，并且在自动提交偏移量之前发生故障，那么就会导致一些消息重复消费或者丢失。”"
  },
  {
    "question": "当Kafka生产者的 `acks` 设置为 `1` 时，以下哪个描述是正确的？",
    "options": [
      "生产者会等待分区的leader副本成功写入消息后就认为发送成功。",
      "生产者会等待所有follower副本都同步完消息后才认为发送成功。",
      "生产者发送消息后立即返回，不等待任何Broker的确认。",
      "生产者会等待ISR中至少一个follower副本（不包括leader）确认消息。"
    ],
    "correctAnswerIndex": 0,
    "explanation": "`acks=1` 是Kafka的默认配置。它在性能和可靠性之间取得了较好的平衡。生产者只需等待leader副本将消息写入其本地日志即可，无需等待follower副本同步。如果在follower同步完成前leader宕机，消息可能会丢失。",
    "source": "文档中「生产端确认机制」部分",
    "hint": "这个设置是“至少一个副本”确认，而第一个能确认消息的副本是谁呢？"
  },
  {
    "question": "为什么在需要高可靠性的业务场景下，推荐使用“手动提交偏移量”而不是自动提交？",
    "options": [
      "因为手动提交的性能远高于自动提交，可以大幅提升消费速度。",
      "因为手动提交是Kafka唯一支持的消费确认方式。",
      "因为它提供了更高的灵活性，允许在业务逻辑处理成功后再提交偏移量，从而避免数据不一致。",
      "因为手动提交可以减少与Kafka集群的网络交互次数。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "手动提交将偏移量管理的控制权交给了开发者。这使得开发者可以在确保消息被成功处理（例如，数据成功写入数据库）之后，才提交偏移量。这种方式能更好地实现“至少一次”的处理语义，有效防止因消费者异常而导致的消息丢失或重复消费问题。",
    "source": "文档中「消费端确认机制」-「手动提交偏移量」部分",
    "hint": "文档中强调手动提交的优势在于“更加灵活”和“确保偏移量提交的准确性”。"
  },
  {
    "question": "Kafka的ACK机制作为一个整体，其核心作用是什么？",
    "options": [
      "专门用于管理消费者的消费进度（偏移量）。",
      "仅用于提高消息发送的性能，不关心消息是否丢失。",
      "允许开发者在消息发送的可靠性和系统性能之间进行权衡和调节。",
      "确保消费者能够以正确的顺序处理来自不同分区的消息。"
    ],
    "correctAnswerIndex": 2,
    "explanation": "ACK机制通过提供 `0`, `1`, `all` 三种不同的配置选项，允许开发者根据业务需求，在消息的可靠性（确保消息不丢失）和性能（发送延迟和吞吐量）之间做出选择。这是一个典型的系统设计中的权衡。",
    "source": "文档中「基本概念」-「性能调节」部分",
    "hint": "文档在“基本概念”中提到了ACK机制的四大作用，其中“性能调节”是如何描述的？"
  },
  {
    "question": "在提供的Java代码示例中，使用哪个`ProducerConfig`常量来设置ACK确认机制？",
    "options": [
      "ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG",
      "ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG",
      "ProducerConfig.BOOTSTRAP_SERVERS_CONFIG",
      "ProducerConfig.ACKS_CONFIG"
    ],
    "correctAnswerIndex": 3,
    "explanation": "在Java Kafka客户端中，生产者的各项参数通过`ProducerConfig`类中的常量进行设置。`ACKS_CONFIG`就是专门用于定义生产者确认级别（`acks`）的键，其值可以是'0', '1', 或 'all'。",
    "source": "文档中「生产端确认机制」-「Java代码配置如下」部分",
    "hint": "请仔细观察Java代码配置示例，找到注释为“设置ACK机制”的那一行代码使用了哪个常量。"
  }
];
        console.log("Quiz Data:", JSON.parse(JSON.stringify(quizData))); // 添加这行用于调试，以可展开的JSON格式输出
        
        let currentQuestionIndex = 0;
        let score = 0;
        // 存储每个问题的回答状态
        const userAnswers = new Array(quizData.length).fill(null); 

        const questionTextEl = document.getElementById('question-text');
        const optionsListEl = document.getElementById('options-list');
        const resultContainerEl = document.getElementById('result-container');
        const quizContentEl = document.getElementById('quiz-content');
        const progressIndicatorEl = document.getElementById('progress-indicator');
        const prevBtn = document.getElementById('prev-btn');
        const nextBtn = document.getElementById('next-btn');
        const hintBtn = document.getElementById('hint-btn');
        const hintContainerEl = document.getElementById('hint-container');

        function loadQuestion() {
          resultContainerEl.innerHTML = '';
          optionsListEl.innerHTML = '';
          hintContainerEl.style.display = 'none'; // 隐藏提示
          
          if (currentQuestionIndex >= quizData.length) {
            showFinalScore();
            return;
          }

          updateProgress();

          const currentQuestion = quizData[currentQuestionIndex];
          questionTextEl.textContent = `(${currentQuestionIndex + 1}/${quizData.length}) ${currentQuestion.question}`;
          
          currentQuestion.options.forEach((optionText, index) => {
            const li = document.createElement('li');
            li.className = 'option-item';
            li.textContent = optionText;
            li.dataset.index = index; // Store index in a data attribute
            // 如果这道题已经回答过，恢复状态
            if (userAnswers[currentQuestionIndex] !== null) {
                if (index === userAnswers[currentQuestionIndex]) {
                    li.classList.add('selected');
                }
            }
            optionsListEl.appendChild(li);
          });

          // 如果已经回答过，直接显示结果
          if (userAnswers[currentQuestionIndex] !== null) {
              const isCorrect = userAnswers[currentQuestionIndex] === currentQuestion.correctAnswerIndex;
              showResult(isCorrect, currentQuestion);
          }
          
          updateNavigationButtons();
          updateProgress();
        }

        function selectOption(optionIndex) {
            userAnswers[currentQuestionIndex] = optionIndex;
            const currentQuestion = quizData[currentQuestionIndex];
            const isCorrect = optionIndex === currentQuestion.correctAnswerIndex;

            // 重新计算分数
            score = userAnswers.reduce((acc, answer, index) => {
                return answer === quizData[index].correctAnswerIndex ? acc + 1 : acc;
            }, 0);

            showResult(isCorrect, currentQuestion);
            updateNavigationButtons();
        }
        
        function updateProgress() {
            const answeredQuestions = userAnswers.filter(answer => answer !== null).length;
            const progressPercentage = (answeredQuestions / quizData.length) * 100;
            progressIndicatorEl.style.width = `${progressPercentage}%`;
        }
        
        function updateNavigationButtons() {
            prevBtn.style.display = 'block';
            nextBtn.style.display = 'block';
            hintBtn.style.display = 'block'; // 显示提示按钮

            prevBtn.disabled = currentQuestionIndex === 0;
            nextBtn.disabled = false; // 最后一题时，下一题按钮不禁用，而是用于显示报告
            nextBtn.textContent = (currentQuestionIndex === quizData.length - 1) ? '查看报告' : '下一题';
            
            // 如果当前问题没有提示，则禁用提示按钮并隐藏提示内容
            if (!quizData[currentQuestionIndex].hint) {
                hintBtn.disabled = true;
                hintContainerEl.style.display = 'none';
                hintContainerEl.textContent = ''; // 清除旧的提示内容
            } else {
                hintBtn.disabled = false;
            }
        }

        function showResult(isCorrect, questionData) {
            resultContainerEl.innerHTML = ''; // 清空之前的结果
            const resultBox = document.createElement('div');
            resultBox.className = `result-box ${isCorrect ? 'correct' : 'incorrect'}`;
            
            let html = `<h3>${isCorrect ? '回答正确！' : '回答错误'}</h3>`;
            if (!isCorrect) {
                html += `<p><strong>正确答案是：</strong> ${questionData.options[questionData.correctAnswerIndex]}</p>`;
            }
            html += `<div class="explanation-text">${questionData.explanation}</div>`;
            html += `<div class="source-text">来源: ${questionData.source}</div>`;
            
            resultBox.innerHTML = html;
            resultContainerEl.appendChild(resultBox);

            // 禁用所有选项的点击事件，并高亮正确/错误答案
            Array.from(optionsListEl.children).forEach((child, index) => {
                child.style.pointerEvents = 'none';
                // 高亮正确答案
                if (index === questionData.correctAnswerIndex) {
                    child.classList.add('correct'); // 需要添加CSS样式
                    child.style.backgroundColor = '#d4edda';
                    child.style.borderColor = '#c3e6cb';
                }
                // 如果选错了，高亮错误选项
                if (!isCorrect && index === userAnswers[currentQuestionIndex]) {
                    child.classList.add('incorrect'); // 需要添加CSS样式
                    child.style.backgroundColor = '#f8d7da';
                    child.style.borderColor = '#f5c6cb';
                }
            });
        }

        function goToNextQuestion() {
            if (currentQuestionIndex < quizData.length - 1) {
                currentQuestionIndex++;
                loadQuestion();
            } else {
                showFinalScore();
            }
        }

        function goToPreviousQuestion() {
            if (currentQuestionIndex > 0) {
                currentQuestionIndex--;
                loadQuestion();
            }
        }
        
        function showHint() {
            const currentQuestion = quizData[currentQuestionIndex];
            if (currentQuestion.hint) {
                hintContainerEl.textContent = currentQuestion.hint;
                hintContainerEl.style.display = 'block';
            } else {
                hintContainerEl.style.display = 'none';
            }
        }

        function showFinalScore() {
            document.querySelector('.quiz-body').style.display = 'none';
            document.getElementById('quiz-footer').style.display = 'none';

            const correctCount = score;
            const totalQuestions = quizData.length;
            const answeredCount = userAnswers.filter(a => a !== null).length;
            const wrongCount = answeredCount - correctCount;
            const skippedCount = totalQuestions - answeredCount;
            const accuracy = totalQuestions > 0 ? Math.round((correctCount / totalQuestions) * 100) : 0;
            const errorRate = totalQuestions > 0 ? Math.round((wrongCount / totalQuestions) * 100) : 0;

            const finalScoreHtml =
                '<div class="final-score-container">' +
                '<h2>答题报告</h2>' +
                '<div class="score-summary">' +
                '<div class="score-card">' +
                '<h3>得分</h3>' +
                '<p>' + correctCount + ' / ' + totalQuestions + '</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>正确率</h3>' +
                '<p>' + accuracy + '%</p>' +
                '</div>' +
                '<div class="score-card">' +
                '<h3>错误率</h3>' +
                '<p>' + errorRate + '%</p>' +
                '</div>' +
                '<div class="score-card score-details">' +
                '<table>' +
                '<tr><td>正确</td><td>' + correctCount + '</td></tr>' +
                '<tr><td>错误</td><td>' + wrongCount + '</td></tr>' +
                '<tr><td>未答</td><td>' + skippedCount + '</td></tr>' +
                '</table>' +
                '</div>' +
                '</div>' +
                '<div class="report-actions">' +
                '<button id="review-btn">回顾测验</button>' +
                '<button class="primary" onclick="location.reload()">再试一次</button>' +
                '</div>' +
                '</div>';

            let reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }
            quizContentEl.insertAdjacentHTML('beforeend', finalScoreHtml);
            document.getElementById('review-btn').addEventListener('click', reviewQuiz);
        }

        function reviewQuiz() {
            const reportEl = document.querySelector('.final-score-container');
            if (reportEl) {
                reportEl.remove();
            }

            document.querySelector('.quiz-body').style.display = 'block';
            document.getElementById('quiz-footer').style.display = 'flex';
            
            currentQuestionIndex = 0;
            loadQuestion();
            updateNavigationButtons(); // Ensure nav buttons are correctly displayed
        }

        // Event Delegation for options
        optionsListEl.addEventListener('click', (event) => {
            if (event.target && event.target.matches('li.option-item')) {
                // Check if the question has already been answered
                if (userAnswers[currentQuestionIndex] === null) {
                    const selectedIndex = parseInt(event.target.dataset.index, 10);
                    selectOption(selectedIndex);
                }
            }
        });

        prevBtn.addEventListener('click', goToPreviousQuestion);
        nextBtn.addEventListener('click', goToNextQuestion);
        hintBtn.addEventListener('click', showHint);
        
        // 初始加载
        loadQuestion();
      </script>
    </body>
    </html>
  